Rail yards and train depots perform important services such as freight distribution, railcar interchange and termination, and railcar inspection and maintenance. Therefore, management of railcars in the yards and depots is important for efficient railroad operation. Therefore, there is a need for a system that can provide real-time information on the location and status of railcars in the yards and depots.
U.S. Pat. No. 6,637,703 describes a system for tracking railcars by using an automated equipment identification (AEI) reader, which is also called as radio frequency identification (RFID) reader, and elevated cameras. Railcars in a yard are tracked by recognizing patterns in video images acquired by the cameras, and signals acquired by the readers. In general, it is known that pattern recognition is less accurate and less reliable for moving objects under changing lighting conditions.
U.S. Pat. No. 6,511,023 describes a system for tracking railcars by using AEI readers and wheel counting stations. A train traveling on a track is identified by the AEI readers. The wheel counting stations are located between the AEI readers to augment the identification locations. However, trains with the same number of wheels cannot be distinguished by that system. This is a particular problem in a rail yard or train depot where most trains are either relatively short, e.g., a single railcar, or the number of railcars in a train is changing dynamically.
U.S. Pat. No. 6,377,877 describes a system for tracking railcars by comparing a location and an itinerary of a railcar. The location is acquired from a GPS system. Because the railcar is not identified specifically, incorrect information can be collected.
U.S. Patent Application Publication 2005/0205719 describes a system for tracking a railcar equipped with an on-board communication system, including a location determining system and a transceiver for receiving and transmitting railcar data. The on-board system requires a power source and maintenance, increasing the cost of the system.
It is desired to provide a railcar tracking system and method that can accurately and reliably locate railcars in real-time in rail yards and train depots.